Laying the foundation of one’s house on another’s wall

Question

Question: On Zayd’s wall — from beneath which the water of Zayd’s house used to drain, and which was the dividing boundary between the two houses — Umar has laid the foundation of his house. What is the ruling on this? Explain and be rewarded.

Answer

If this wall is Zayd’s property, then it is impermissible for Umar to lay the foundation of his house on Zayd’s wall without Zayd’s permission.

Source: Fatawa Mahmudiyya

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